Ferrofluid

A ferrofluid (portmanteau of ferromagnetic and fluid) is a liquid that becomes strongly magnetized in the presence of a magnetic field.
A grinding process for ferrofluid was invented in 1963 by NASA's Steve Papell as a liquid rocket fuel that could be drawn toward a pump inlet in a weightless environment by applying a magnetic field. The name ferrofluid was introduced, the process improved, more highly magnetic liquids synthesized (see figure on right), additional carrier liquids discovered, and the physical chemistry elucidated by R.E.Rosensweig and colleagues; in addition Rosensweig evolved a new branch of fluid mechanics termed ferrohydrodynamics.